LAPATINIB (Generic for TYKERB)

Lapatinib 250mg, Oral tablet

Grapefruit juice

· Severity: Major

· Notes for Consumers: Do not take Lapatinib with Grapefruit or Grapefruit juice. Side effects of Lapatinib may get worse. If you accidentally take Lapatinib with grapefruit or grapefruit juice, immediately tell your doctor about any unusual effects.

· Notes for Professionals: Avoid administration of lapatinib with grapefruit juice due to increased plasma concentrations of lapatinib. Lapatinib is a CYP3A4 substrate and grapefruit juice is a strong CYP3A4 inhibitor. Concomitant use with another strong CYP3A4 inhibitor increased lapatinib exposure by 3.6-fold and increased the half-life of lapatinib by 1.7-fold.

Lapatinib 250mg, Oral tablet

Marijuana

· Severity: Moderate

· Notes for Consumers: Lapatinib can theoretically decrease the elimination of Marijuana, Medical from the body. Side effects from Marijuana, Medical may worsen if you take Lapatinib. You may feel drowsy or more tired. Do not drive or operate machinery until you know how these drugs affect you. Contact your health care provider immediately if you notice slurred speech, confusion, increases heart rate, or palpitations while taking Marijuana, Medical.

· Notes for Professionals: The incidence of marijuana associated adverse effects may change following coadministration with lapatinib. Lapatinib is an inhibitor of CYP3A4, an isoenzyme partially responsible for the metabolism of marijuana's most psychoactive compound, delta-9-tetrahydrocannabinol (Delta-9-THC). When given concurrently with lapatinib, the amount of Delta-9-THC converted to the active metabolite 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC) may be reduced. These changes in Delta-9-THC and 11-OH-THC plasma concentrations may result in an altered marijuana adverse event profile.

<b>DISCLAIMER:</b><em> This drug information content is provided for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Patients should always consult their physician with any questions regarding a medical condition and to obtain medical advice and treatment. Drug information is sourced from GSDD (Gold Standard Drug Database ) provided by Elsevier.</em>